A study called Effect of a popular Middle Eastern food (Falafel) on rat liver is now available to the public. Focusing strictly on the medical consequences (for rats) of eating "chickpeas paste seasoned with garlic, parsley, and special spices, then deep fried in vegetable oil", it's a 10-page journey from delight to despair, and finally to indifference.

Sana Janakat and Mohammad Al-Khateeb of the Jordan University of Science and Technology in Irbid, Jordan, wrote the report. It somewhat enlivens the February 2011 issue of the journal Toxicological & Environmental Chemistry.

Janakat and Al-Khateeb start with some cheery praise: "Falafel is considered the most popular fried food by all socio-economic classes in most Middle Eastern countries. It is consumed for breakfast, dinner, or as a snack. Among low-income families and labourers it is consumed on a daily basis, due to its availability, relatively low price, and good taste."

Then come several pages of unhappy news that lead to a depressing and technical conclusion: "Long-term consumption of falafel patties caused a significant increase in ALP [alkaline phosphatase], ALT [alanine transaminase], bilirubin level and increased liver weight/body weight ratio ... This indicates that consumption of large amounts of falafel on daily basis might lead to hepatotoxicity."

But wait! That's not the end of the story.

Here's what Janakat and Al-Khateeb say they did.

First they gathered falafel: "Frying oil samples and falafel patties were collected from 20 restaurants located in different socio-economic neighbourhoods from the city of Irbid."

They homogenized the falafel, soaked it for 24 hours, filtered it through cheesecloth and centrifuged it. This produced the experimental material – concentrated falafel – with which they performed two experiments.

The first experiment assessed the short-term effect of eating falafel, short term in this case meaning five days. Janakat and Al-Khateeb extracted the oil from some falafel patties, and force-fed it to some rats for the whole five days. Then they killed those rats, and did post mortems to get at the livers. The livers (happily, in a sense) looked in pretty good shape. Thus, the report says, the short-term effects of eating falafel are pretty benign.

The second experiment aimed to clarify the long-term effect of falafel consumption. A fresh batch of rats got to eat lots of falafel – as much as they pleased, whenever they wanted it – for a month. That was their entire diet: falafel, falafel, falafel. Then they were killed. Here, the post mortem results were ugly. The study intones that "long-term consumption of falafel patties (30 days) caused yellowish discoloration of the liver distinctive of liver necrosis", suggesting that "the consumption of falafel as the sole source of nutrition for a long period of time ... can generate a hepatotoxic effect leading to liver necrosis".

That may sound like bad news, but apparently it's not. The very next sentence – nearly the last thing said in the report – is this: "Falafel consumption in moderation and in conjunction with other food items or beverages containing high antioxidant levels can be considered as safe."

• Marc Abrahams is editor of the bimonthly Annals of Improbable Research and organiser of the Ig Nobel prize